.TH sbcast "1" "Slurm Commands" "October 2016" "Slurm Commands"

.SH "NAME"
sbcast \- transmit a file to the nodes allocated to a Slurm job.

.SH "SYNOPSIS"
\fBsbcast\fR [\-CfFjpstvV] SOURCE DEST

.SH "DESCRIPTION"
\fBsbcast\fR is used to transmit a file to all nodes allocated
to the currently active Slurm job.
This command should only be executed from within a Slurm batch
job or within the shell spawned after a Slurm job's resource
allocation.
\fBSOURCE\fR is the name of a file on the current node.
\fBDEST\fR should be the fully qualified pathname for the
file copy to be created on each node.
If a fully qualified pathname is not provided, the file will be created in
the directory specified in the \fBSbcastParameters\fR parameter in the slurm.conf
file (if available) otherwise it will be created in the current working
directory from which the sbcast command is invoked.
\fBDEST\fR should be on a file system local to that node.
Note that parallel file systems \fImay\fR provide better performance
than \fBsbcast\fR can provide, although performance will vary
by file size, degree of parallelism, and network type.

.SH "OPTIONS"
.TP
\fB\-C\fR [\fIlibrary\fR], \fB\-\-compress\fR[=\fIlibrary\fR]
Compress the file being transmitted.
The optional argument specifies the data compression library to be used.
Supported values are "lz4" (default), "none" and "zlib".
Some compression libraries may be unavailable on some systems.
The default compression library (and enabling compression itself) may be
set in the slurm.conf file using the SbcastParameter option.
.TP
\fB\-f\fR, \fB\-\-force\fR
If the destination file already exists, replace it.
.TP
\fB\-F\fR \fInumber\fR, \fB\-\-fanout\fR=\fInumber\fR
Specify the fanout of messages used for file transfer.
Maximum value is currently eight.
.TP
\fB\-j\fR \fIjobID[.stepID]\fR, \fB\-\-jobid\fR=\fIjobID[.stepID]\fR
Specify the job ID to use with optional step ID.  If run inside an allocation
this is unneeded as the job ID will read from the environment.
.TP
\fB\-p\fR, \fB\-\-preserve\fR
Preserves modification times, access times, and modes from the
original file.
.TP
\fB\-s\fR \fIsize\fR, \fB\-\-size\fR=\fIsize\fR
Specify the block size used for file broadcast.
The size can have a suffix of \fIk\fR or \fIm\fR for kilobytes
or megabytes respectively (defaults to bytes).
This size subject to rounding and range limits to maintain
good performance.
The default value is the file size or 8MB, whichever is smaller.
This value may need to be set on systems with very limited memory.
.TP
\fB\-t\fB \fIseconds\fR, fB\-\-timeout\fR=\fIseconds\fR
Specify the message timeout in seconds.
The default value is \fIMessageTimeout\fR as reported by
"scontrol show config".
Setting a higher value may be necessitated by relatively slow
I/O performance on the compute node disks.
.TP
\fB\-v\fR, \fB\-\-verbose\fR
Provide detailed event logging through program execution.
.TP
\fB\-V\fR, \fB\-\-version\fR
Print version information and exit.

.SH "ENVIRONMENT VARIABLES"
.PP
Some \fBsbcast\fR options may be set via environment variables.
These environment variables, along with their corresponding options,
are listed below. (Note: Command line options will always override
these settings.)
.TP 20
\fBSBCAST_COMPRESS\fR
\fB\-C, \-\-compress\fR
.TP
\fBSBCAST_FANOUT\fR
\fB\-F\fB \fInumber\fR, fB\-\-fanout\fR=\fInumber\fR
.TP
\fBSBCAST_FORCE\fR
\fB\-f, \-\-force\fR
.TP
\fBSBCAST_PRESERVE\fR
\fB\-p, \-\-preserve\fR
.TP
\fBSBCAST_SIZE\fR
\fB\-s\fR \fIsize\fR, \fB\-\-size\fR=\fIsize\fR
.TP
\fBSBCAST_TIMEOUT\fR
\fB\-t\fB \fIseconds\fR, fB\-\-timeout\fR=\fIseconds\fR
.TP
\fBSLURM_CONF\fR
The location of the Slurm configuration file.

.SH "AUTHORIZATION"

When using the Slurm db, users who have AdminLevel's defined (Operator
or Admin) and users who are account coordinators are given the
authority to invoke sbcast on other user's jobs.

.SH "EXAMPLE"

Using a batch script, transmit local file \fBmy.prog\fR to
\fB/tmp/my.proc\fR on the local nodes and then execute it.

.nf
> cat my.job
#!/bin/bash
sbcast my.prog /tmp/my.prog
srun /tmp/my.prog

> sbatch \-\-nodes=8 my.job
srun: jobid 12345 submitted
.fi

.SH "COPYING"
Copyright (C) 2006-2010 The Regents of the University of California.
Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
.br
Copyright (C) 2010\-2016 SchedMD LLC.
.LP
This file is part of Slurm, a resource management program.
For details, see <https://slurm.schedmd.com/>.
.LP
Slurm is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your option)
any later version.
.LP
Slurm is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
details.

.SH "SEE ALSO"
\fBsrun\fR(1)
